Gauge

iTrader: (3)

Hey all,

Here are my mods (cut and paste from sig, so lots of non-power-related stuff) and my dyno sheet. She put down 400/364 on a Mustang dyno. What should I expect on a Dynojet?


Mods:
SLP lid, K&N, SLP underdrive pulley, TR 230/236, Crane Cams springs, TR chrome-moly pushrods, QTP 1-3/4" LTs, QTP catted Y, Hooker catback, custom cutouts, tune by HPE, Strange Dana S60 w/ 4.10s, poly tranny mount, Pro 5.0, Textralia, G2 LCAs (rod/poly), Spohn adj. T/A (tranny mounted), Bilstein HDs, Brembos, Hawk HPS pads, 275 Nitto 555Rs, !AIR, !CAGS, and !molding.

Patrick G

iTrader: (14)

Hard to say as Mustang dynos vary a great deal. I've seen HPE's Mustang dynos be a lot closer to Dynojet numbers than most. For tuning, Mustang dynos are the best. For bragging rights, it's hard to get a big number out of them.

Gauge

iTrader: (3)

In any case, I'm certainly happy with the numbers. It's not too big of a cam, so my expectations were lower than the results.

2muchTA4U

man what was being used for rpm pick up and I wouldn't even put that graph up with it looking that way.. and I take it that wide band wasn't even hooked up??? looks like it was only pulled once maybe twice?? why is that?? don't seem like you went to learn much from your visit to the dyno with a crappy graph and no a/f

dynocar

I was wondering if anyone would question it, how refreshing. I would seriously question any numbers on it, much less, quote them.

Nate81Camaro

H T S
O T H K L RD H
L I I O I U Y P
Y H S O K O N A
S L EY O R
G

Nate81Camaro

*EDITED: couldn't put up what I wanted to....

Gauge

iTrader: (3)

1) Define "rpm pick up."
2) I assumed that a wide band was used. HPE is definitely a reputable shop, so I would freakin' hope so. He did say it was running lean up top, so he had to find that out somehow.
3) It was pulled four times. The sheet only shows the last one.

2muchTA4U

well he either done a roll speed calibration to pick up rpm if your a manual car or he used the inductive on the coil wires going into the coil itself not the plug wire.. if a plug wire was used I think this may have cause the sketchiness in the graph but hard to say as that one of the worst looking graphs I have seen.. and I am in no way ******* HPE. and the a/f I only said it didn't looked hooked up as the avg.. on your a/f was in the 7.xx range.. I know if we leave ours turned off the display will say like 7 to 8 a/f with nothing hooked up to it or powered up.. only reason I said a/f didn't look hooked up.. maybe dynocar or someone will back me or correct me if I am wrong here.

2muchTA4U

BTW for the mods you have your power is good.. just curious was this dyno run ran through virtual simulation on their dyno? if so do you know the numbers used on the cars weight and hp@50.. and you most likely will not know the answers to these questions but thought I would ask any..400 with just a cam on a MD is some damn fine numbers.. if the numbers are correct.. again maybe someone will correct me or are thinking the same as me.. we will see if anyone replies.

slow

iTrader: (7)

That must be from the tach pickup, the roll speed can't drop out, and still give you good dyno data.

The tach pickup that comes on the mustang dyno's is not that great (if it is the smart tach) I use rollspeed all the time, and it is very stable.

Ryan

dynocar

We use "smart tach" all the time, rarely a problem, if we do have a problem we use the smart tach's optical pickup, most accurate. We never use roll speed because it is impossible to get an exact MPH/RPM ratio due to many factors, such as tire growth as the MPH increases. Auto trans cars, especially higher stall speeds really throw the ratio off. Keep in mind, the dyno's calculations depend on accurate RPM readings.

DynoDR

iTrader: (1)

I use the Smart Tach also without any problems. Although I do use the Optical pickup on about everything.

dynocar

Most Smart Tach problems are caused by the flimsy inductive pickup provided. We are constantly repairing or replacing ours. Always check the pickup's ohm readings at its plug, around 4 ohms if I recall correctly.

mike c.

iTrader: (1)

a few years ago on an old set up of mine i was on a dyno jet and got 391hp then went to a mustang dyno a week later and got 370hp. nothing at all changed on the car between the two dyno sessions. to say the least,i was ready to cry after seeing the mustang dyno #'s. today i dyno 463hp & 413.8tq on the same mustang dyno that almost made me cry.

2muchTA4U

yes we only roll speed manual cars with radial tires all others get a rpm signal through a primary feed.

99blancoSS

iTrader: (115)

Theres no set factor but 8-12 percent seems to be about the norm. You can "unload" the Mustang Dyno to get better numbers if thats what you really wanted to do. A Mustang Dyno is a better tuning tool and gives better actual real world hp and tq rating's as compared to a dyno jet which just spins freely.

dynocar

Unloading a Mustang, or any dyno will decrease the HP/TQ readings, which most would not consider "better numbers", I don't think.

99blancoSS

iTrader: (115)

Unloading will release the resistance on the rollers and allow them to spin freely like a dynojet. Not sure how you think this will decrease numbers. Your decreasing resistance so you numbers will improve. This is the basic difference between the two styles in the first place and is why a mustang dyno is a superior tuning tool to a regular dynojet. ( I hear dynojet makes one as well but most shops dont have it) I believe its called an eddy current..(not sure on the terminology)

2muchTA4U

eddy current is not a dyno jet trade nor did they opt to use it till many years later after everyone wised up and found out what UH LOAD MATTERS! lol.. and what do you think a mustang dyno uses for load??? it has a eddy current load absoroption cell. two in some cases.